The present invention relates to ignition systems of the type used with internal combustion engines, rotating turbine engines and the like. More particularly, the present invention relates to the generation of timing signals for controlling the operation of such ignition systems.
Capacitive discharge type ignition circuits are commonly used in ignition systems for automobiles. Heretofore, the operation of these ignition systems has been generally controlled by the use of mechanical breaker contacts or points to generate timing signals. The breaker contacts are opened and closed in synchronism with the movements of the pistons of an associated engine by a rotating cam in the distributor of the engine. Thereby, the discharge of a storage capacitor in the capacitive discharge type ignition circuit through the primary of an ignition coil is timed so that ignition sparks are delivered in a timed sequence to ignite combustible fuel which provides the energy to drive the engine.
A disadvantage with the use of breaker contacts or points for generating these timing signals is that they are unreliable, being subject to contact bounce, sticking and like problems associated with failure of the contacts to properly open or close.